The goal of this SBIR phase II project is to evaluate the efficacy of a mobile technology based system to increase the proportion of primary care patients who are successfully linked to and receive indicated follow up specialty substance-use-disorders (SUD) care. The system should demonstrate that it can enable primary care practices to better implement substance abuse prevention guidelines, such as ?Screening, Brief Intervention, and Referral to Treatment (SBIRT).? The system engages both patients and clinicians for Shared Decision-Making (SDM) in the primary care setting, and follows through the decisions after the patient goes home. The system will be guided by the latest research on cognitive design in healthcare IT systems, and be evaluated in a real world primary care clinic for acceptance and engagement.